Refrigerating apparatus



Feb. 13, 1923.

N. G. ANDER$ON.

REFRIGERATING APPARATUS.

2 SHEETSSHEET I.

FILED MAR. 4. 1920.

(73 Q I W falam C} Feb. 13, 1923.

N. G. ANDERSON.

REFRIGERATING APPARATUS.

2 SHEETS SHEET 2.

FILED MAR. 4, I920.

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UNITED STATES NELSON G; ANDERSON, OF CHICAGO, ILLINOIS.

REFRIGE RATING APPARATUS.

Application filed March 4, 1920. Serial No. 363,265.

To all whom it may concern Be it known that I, NELSON G. ANnnnsoN, acitizen of the United States, residing at Chicago, in the county of Cookand State of Illinois, have invented a certain new and usefulImprovement in Refrigerating Apparatus, of which the following is afull, clear, concise, and exact description. reference being had to theaccompanying drawings, forming apart of this specification.

My invention relates to refrigerating apparatus and more particularly torefrigerating apparatus of the well known compression type wherein aliquefia-ble gas such as ammonia is mechanically compressed for coolingor refrigerating purposes. 1

One of the objects of this invention is to provide an apparatus of thistype wherein various elements are so improved in design and constructionthat the apparatus as an entirety is rendered more compact, durable andeflicient. so that it is better adapted for use in refrigerating systemssuch as are in general domestic use.

Other objects will more definitely appear from the followingdescription, in which reference is made to the accompanying drawingsillustrating the invention.

In the drawings Figure 1 is a front elevation of a refrigerator whereinthe improved refrigerating apparatus of my invention is installed;

Fi ure 2 a side elevation of a portion of the refrigerator apparatus,consisting briefly of the compressor.condensor and the motor for drivingthe compressor.

Figure 3 is a plan view of an improved control mechanism which I preferto provide for controlling the flow of the cooling fluid and also theoperation of the motor for driving the compressor; and

Figure 4 is a diagrammatic view of the circuit connections which aresecured by the control mechanism shown in Figure 3.

The same reference numerals will be used to designate like partsthroughout the following detailed description.

It will be understood that while the invention is shown as embodied in arefrigerating machine of the compression type and installed in arefrigerator of the kind generally in domestic use as exemplified by therefrigerator shown in Figure 1. certain features of my invention areapplicable to refrigerating systems of various types and forms. 7

are indicated respectively by the reference,

numerals 15, 16 and 17. The compressor comprises a crank case 18, inwhich is journaled a crank shaft 19. A connecting rod 20 connects thecrank shaft with an elongated comp-ressor piston 21. which is providedwith a comparatively large number of piston rings to prevent leakagepast the piston of ammonia vapors on compression strokes. The piston 21is arranged to reciprocate in the compressor cylinder 22. which isbolted upon a cylindrical extension 23 0f the crank case 18. Thedim-neter of the compressor cylinder 22 is so -a-roportioned withrespect to the cylindrical exten sion 23 that a rather substantialshoulder 2-L is afforded. This shoulder prevents oil from the crank casefrom entering the cylinder 22. so that the ammonia vapor compressed inthe cylinder cannot-be contaminated. The upper part of the cylinder 22is provided with lugs which receive bolts to clamp down the cylinderhead 25. The unnular groove 26 in the wall of the cylinder 22 receives adisk valve 527.

spring 28. Formed integral and concentric with the cylinder 22 is awater jacket 29, which is suitably provided with a cap 29'. Extendingbetween the cylinder wall and the water jacket 29 are webs 30. 30, whichare internally screwthreaded to receive the pipes 31 and 32.

The pipe 31 communicates with the condensing coil 33 through a combinedunion which is held in. engagement with its seat by a compression andcheck valve shown at 34. This con'ibined union and check valve comprisesthe two disk Q shaped clamping members 35, which are suitably boltedt'ogetherto clamp between them a lead gasket to form a fluid tightjoint. One of these membe'rsis prov ded.

compact apparatus.

with a hollow cylindrical boss which is internally screwthreaded toreceive a bushing,

' in which the end of the pipe 31 is threaded.

ent of the valve, but by combining the two/ as here described, aconsiderable saving in space is effected, which results in a mor Thepipe 32 communicates with the discharge end of the expansion coi 33. andre ceives the vaporized ammon a, which has performed its refrigeratingfunction in the refrigerating chamber 11 of the refrigerator,

The condensing coil 33 communicates at its lower end with a recei er 39,which comprises the two cup shap d cylindrical mem bers 39 and 39suitably welded together at their edges. as shown, to form a closedreceptacle. The receiver 39 fits closely within a depression 40 in thebase 14 so as to provide only a slight space between its walls and the'walls of the depression. A hood 41 is bolted down upon the base overthe depression 40 and entlrely surrounds the condensing C011 33. Aremovable cover 42 closes the upper end of the hood 41 thereby forming aclosedwater jacket for the condenser and receiver. A pipe 43 hascommunication through a valve 44 with a source of cooling fluid underpressure. The cooling fluid coming from the pipe 43 enters the waterjacket at the depression, passes upwardly in the space around thereceiver walls and then up and around the condensing coil 33 and outthrough the pipe 45 and into the water jacket 29 of the compressorcylinder 22. After circulating about the compressor cylinder the fluidis discharged through pipe 46, which may have communication with thesewer or other waste receptacle. In this way the refrigerant receiver 39is cooled to the lowest possible temperature and to the lowesttemperature of the cooling fluid circuit.

Permanent gases are frequently formed in refrigerating plants and are agreat source of nuisance. principally because they interfere with thecorrect indications of gages and with the efficient working .of theplant generally. These gases are formed usually through thedecomposition ,of the ammonia into its constituent elements.'Ihisdecomposition is generally brought about through improper orinsufficient cooling of therefrigerant receiverand condensing coil andof the compressorcylinder. It is, therefore, of utmost importance thatthe cooling of certain refrigerator elements be accomplished withcertainty and that any unnecessary and undesirable obstructions to theflow of cooling fluid be avoided. I

I provide a series of circular baflie plates 4T. 47 and 47', which aresecured to the, braces 48, which support and space the convolutions ofthe condensing coil 33. The coolingfluid, which would ordinarily take apath of least resistance that is, directly up through the centralopening iu the coil 33, is thereby forced to assume a path approximatingthat of the arrows "shown in Figure 2. r w

\Vith the aforesaid p'urpose in view. a series of lugs in place of aflange is provided on the compressor cylinder 22, to affordmeans/towhich to clamp the head 25: I This construction avoids a seriousobstruction to the flow of the cooling fluid. 1.

The electric motor 17 is mounted'on the base 14 on that side of thecondensing unit 16 away from the compressor 15. The motor 17 drives thecompressor 15 through a belt 49, which passes around the pulley 50,which is keyed or otherwise secured on the crank shaft 19 of thecompressor.

An idler pulley 51, secured to the free end of an arm 52. which ispivoted at 53 to the base 14, is arranged to exert a constant downwardpull upon the belt 49 through the medium of a tension spring 54. Thetension of the belt 49 is therefore always constant.

The electric motor 17 is connected to a source of current through thesnap switch A pipe 56 is connected to the lower part of the receiver 39through a union (not shown), and communicates with the expansion coil 33through an expansion valve 57, which may be of conventional design.

The operation of the apparatus thus far described is as follows:

The refrigerant in a gaseous state is drawn into the compressor cylinder22 through the pipe 32 as the piston 21 reaches its lower dead center.As the piston r ses on its return upstroke. the gaseous refrigerant iscoma pressed. The valve 2! is forced off its seat against the tension ofthe spring 28.? The compressed gas by-passes through a plurality ofchannels 58 formed in the cylinder wall, and enters the pipe 31. whereit is forced through the non-return or check valve 37 into thecondensing coil 33. The temperature of the compressed gas is thensubstantially thatof the cooling fluid. The refrigerant liquefies anddischarges into the re-- ceiver 39, from which point it is forcedthrough the pipe 56'and the expansion valve 57 into the expansion ,coil33. The expan sion valve 57has a pressure reducing opening, and. astherefrigerant passes through this opening, a great reduction in pressureresults. The refrigerant consequently evap-.

orates, resulting in a considerable reduction in temperature'of therefrigerating medium,

which thereby extracts heat from the air or other fluid which surroundsthe coil. The vapor is then returned under pressure to the compressorcylinder, through the pipe 31, and the process is repeated continuously.

To insure efficient functioning of the refrigerating apparatus, it isessential at certain times that the compressor cease to operate, as whenthe temperature of the refrigerator storage compartments has reached a.predetermined low temperature. A thermostat 58 is provided in thestorage compartment 12, which is operable, as usual, by increases ordecreases in temperature, and serves to regulate the operation of thecompressor and the circulation of the cooling fluid. However, themovement of the thermal element is generally very feeble and uncertain.In various prior devices of this type a very substantial increase ordecrease in temperature is necessary to insure a proper regulation ofthe refrigerating ap paratus. A regulation between narrow limits hastherefore been impossible. I provide, in conjunction with the thermostat58, an improved form of control mechanism indicated generally in Figures1 and 3 by the reference numeral 59. Through the provision of thismechanism the slightest flickering movement of the thermal elementeffects the desired alteration in the further operation of therefrigerating apparatus.

The control mechanism comprises a cornparatively small motor 60, whichis mounted in a suitable channel-shaped frame 61. A worm 62, keyed orotherwise secured to the armature shaft of the motor 60. meshes with aworm gear 63 on the shaft 64. R0- tation of the gear 63 is communicatedto the shaft 65 through a train of reduction gears 66, 67, 68 and 69.Mounted on the shaft 65 adjacent the gear 69 is a drum 70, which carriesthe four interrupter segments 71, 72, 73 and 74, upon which ride theleaf spring brushes 75, 76, 77 and 78 respectively. The outer ends ofthese brushes are mounted on a block of insulation 79.

One end of the shaft 65 projects through the side wall of the frame 61.and is there provided with a clip 80, which embraces the' key 81 of thesnap switch 55. As above stated, the switch 55 controls the operation ofthe motor 17, which drives the compressor. The other end of the shaft 65projects through the other side wall of the frame 61, and is theresecured in the end of the stud shaft 82, which in turn operates thevalve element of the valve 44. The valve 44, as above stated. controlsthe flow of the cooling fluid. which normally circulates around thereceiver. the condensing coil and the compressor cylinder.

The operation of the control mechanism is entirely automatic. Thecompressor is operated to compress the spent refrigerant when thetemperatue of the storage compartments 12 of the refrigerator rises be ieletures to make contact with either one of the contacts 84 or 85 toclose a circuit from the battery 86 through the motor 60, the thermostat58 and the proper interrupter segments of the drum back to the otherside of the battery 86. The interrupter segments are provided withinsulation sectors at such intervals as to permit the motor 60 to runonly long enough to cause the shaft 65 to make a quarter revolution.'Thus the key of the snap SW1lZCl1-55 is continuously rotated in thesame direction to alternately make and break the circuit for the motor17. Likewise the valve element of the valve 44 is continuously rotatedto permit the circulation of the cooling fluid or to stop the same. Thedrum 70 is shown diagrammatically in Figure 4. From an inspection ofFigure 3 it will be seen that the space between the interrupter segments71, 72. 73 and 74 is composed of an electrical conducting material. Thevarious interrupter segments, with the exception of segment 72, areprovided, as aforesaid, with sectors of insulating material. The segment71 has the diametrically oppositely disposed insulation sectors 87 and87. with the diametrically opposed conducting sectors 88 and 88 Thesegment 74 has the diametrically opposed insulation sectors 89 and 89and the conducting portions 90 and 90".

It will be seen that the insulation sectors are not as greatgeometrically as the conducting sectors. The purpose for soproportioning these sectors will presently be obvious.

The interrupter segment 73 is provided with four insulated steps 91. 92.93 and 94. As the drum 70 rotates the leaf spring brush 77 rides on theperiphery of the segment 73 and springs down into a step at everyquarter revolution of the drum.

The control mechanism just described operates as follows: Assuming theapparatus is at rest. and that the temperature of the refrigerator hasreached an undesirably high point. the thermostatic switch element 83makes contact with the lower contact member 85. The following circuit isthereby completed battery 86. conductor 95. motor 60, conductor 96.switch element 83. contact 85. conductor 97. leaf spring brush 75.conducting sector 88 of interrupter segment 71. through the interveningconduct-- ing portion of the drum 7(). through segment 72. brush 76.conductor 98. to the other side of battery 86.

It is found that at times the thermostatic switch element 83 will notmake a good contact with the contact 85, due. perhaps, to the fact thatit is not sufficiently responsive to the slight temperature change whichhas occurred. At such times the contact will be but very feeble andflickering. With this objection in view.'the segment 73 is provided. Itwill appear from Figured that at the moment the above described circuitis closed, the brush 7? is resting on the insulated step 91 of thesegment 73. As soon as the above mentioned circuit is closed the drumcommences to rotate slowly. Almost simultaneously the brush 7? rides offthe insulated step 91 and onto the intervening" conducting portion ofthe segment 73. The following circuit is thereby elosedz battery 86,conductor 95, motor ()0. conductor 96. conductor 99, leaf spring brush7?. segment 73. intervening conducting portion of the drum 70, segment72, 'leaf spring brush 7.6. conductor 98 and back to. the other side ofthe battery 86.

The drum T0 is thereby rotated until the leaf spring brush 75 rides uponinsulation sector 87 anduntil the leaf spring brush TTsprings into theinsulated step 92 of the segment 73. The shaft 65 has thereby completeda quarter revolution and the switch key 81 has been turned to its onposition. The motor 17, and hence the compressor 15 is thereby caused tooperate. Likewise the valve 4% has been opened to permit the flow of thecooling fluid thru pipe 43.

After the above described quarter revolution of the drum 70, the leafspring brush 78 will have passed over the insulation sector 89 and madecontact with conducting sector 90.

After a sufficient interval of time has elapsed wherein therefrigerating apparatus has functioned to bring the temperature of therefrigerator beyond a desirable low point. the thermostatic switchelement 83 will make contact with the contact 84: to close the followingcircuit: battery 86, conductor 95, motor 60, conductor 96, switchelement 83. contact 84. conductor 100, leaf spring brush T8. conductingsect-or 90 of interrupter segment- H, the intervening conducting portionof the drum T0. interrupter segment T2. leaf spring brush 76, conductor98, back to the other side of the battery 86.

As before stated. the contact with the switch element 83 is. at times.very feeble and flickering. To insure at all times the properfunctioning of the control apparatus. and to decrease the detrimentalsparking at the thermostat. contact, the segment 73 is provided asaforesaid. 'hen the above circuit is closed. the drum 7t) commences torotate slowly. lracticallv brush 7? rides off the insulated step 92 ontothe intervening conducting portion of the segment T3. and a circuitparallel with that just above described is closed. This circuit has beendescribed in connection with the simultaneousl v the 8 operation of thecontrol mechanism which results from a rise in temperature of therefrigerator compartments, and, therefore, it need not be repeated. Itwill appear that as above, upo'n acircuit being closed through themotor, the drum will rotate slowly through a quarter revolution,whereupon the leaf spring brush 77 will spring down onto the insulatedstep 93 of the segment 7 Likewise the leaf spring brush 78 will thenassume a position in contact with the insulation sector 89 of thesegment 74.

The brush 75, on the contrary, will ride over the segment 71 intocontact with the conducting sector 88 thereof.

The shaft having rotated through a quarter revolution, the snap switchkey 81 will have beenturned to its off position, and likewise the valve4A will have been closed to prevent further immediate flow of thecooling fluid.

\Vhile I have described the preferred embodiment of my invention, I donot limit myself to the details of construction disclosed, but cover allequivalent embodiments coming within the scope and spirit of theappended claims.

\Vhat. I claim as new and desire to seeure by Letters Patent of theUnited States 1s:

1. A condenser comprising a receptacle,

a receiver fitting closely within said receptacle. a condenser coilconnected with said receiver and disposed adjacent the receptacle wall,an inlet connection for the admission of cooling fluid adjacent the baseof the receptacle and receiver, an outlet for said fluid disposedupwardly from the inlet. a support. bafiie plates secured to thesupport. and adapted to deflect the flow of cooling fluid in its passagefrom the inlet to the outlet around the inner and outer peripheries ofthe condenser coil.

2. A condenser comprising a receptacle, a receiver fitting'within saidreceptacle. a condenser coil connected with said receiver, and disposedadjacent the vertical walls of the receptacle, an inlet connection forthe admission of cooling fluid adjacent the base of the receptacle andreceiver. an outlet for said fluid. a support mounted on the receiverand disposed adjacent the inner periphery of the condenser coil. 'baiileplates secured to the support. the diameter of said baffle plates beingsubstantially the same the inside diameter of the condenser coil. saidbaifie plates being disposed to deflect the passage of cooling fluidaround the inner and outer peripheries of the condenser coil.

In witness whereof. T hereunto subscribe my name this 1st day of March.1920.

NELSON G. ANDERSON.

itnessesz \VARREN DEWER, EDNA V. GUSTAFSON.

